There is conventionally proposed a noise canceling device (acoustic conversion device for active noise control) for suppressing or removing noise around a vehicle (e.g., refer to Patent Literature 1). According to the conventional noise canceling device described in Patent Literature 1, a relation between noise such as engine sound, wind noise and tire friction sound, and a vehicle state such as vehicle type, speed and acceleration is previously stored, and sound having opposite phase to the noise is emitted into a room space of the vehicle in accordance with the vehicle's state, thereby suppressing or removing the noise.